Growth in economies with non convexities: sunspots and lottery equilibria

Summary. We investigate the relation between lotteries and sunspot allocations in a dynamic economy where the utility functions are not concave. In an intertemporal competitive economy, the household consumption set is identified with the set of lotteries, while in the intertemporal sunspot economy it is the set of measurable allocations in the given probability space of sunspots. Sunspot intertemporal equilibria whenever they exist are efficient, independently of the sunspot space specification. If feasibility is, at each point in time, a restriction over the average value of the lotteries, competitive equilibrium prices are linear in basic commodities and intertemporal sunspot and competitive equilibria are equivalent. Two models have this feature: Large economies and economies with semi-linear technologies. We provide examples showing that in general, intertemporal competitive equilibrium prices are non-linear in basic commodities and, hence, intertemporal sunspot equilibria do not exist. The competitive static equilibrium allocations are stationary, intertemporal equilibrium allocations, but the static sunspot equilibria need not to be stationary, intertemporal sunspot equilibria. We construct examples of non-convex economies with indeterminate and Pareto ranked static sunspot equilibrium allocations associated to distinct specifications of the sunspot probability space.Received: 25 August 2003, Revised: 16 March 2004, JEL Classification Numbers: D84, D90.Correspondence to: Paolo SiconolfiWe thank Herakles Polemarchakis for helpful conversations on the topic. The research of Aldo Rustichini was supported by the NSF grant NSF/SES-0136556.     

Moonlighting politicians

In most modern democracies elected officials can work in the private sector while appointed in parliament. We show that when the political and market sectors are not mutually exclusive, a trade-off arises between the quality of elected officials and the time they devote to political life. If high-ability citizens can keep earning money outside of parliament, they will be more likely to run for election; for the same reason, they will also be more likely to shirk once elected. These predictions are confronted with a dataset about members of the Italian Parliament from 1996 to 2006. The empirical evidence shows that bad but dedicated politicians come along with good but not fully committed politicians. There is in fact a non-negligible fraction of citizens with remarkably high pre-election income who are appointed in parliament. These citizens are those who gain relatively more from being elected in terms of outside income. At the same time, they are less committed to the parliamentary activity in terms of voting attendance.     

HEALTH IMPROVEMENTS AND THE TRANSITION OUT OF MALTHUSIAN STAGNATION

The central component of most economic models that analyse the transition from the Malthusian regime to self-sustaining developed economies is education. Improved health is normally envisaged as simply a by-product of economic growth. Whereas growth does, indeed, tend to improve health status, the reverse is also true, namely that health improvements are a dynamic force capable of driving economic expansion. This paper underlines the importance of health improvements in escaping from Malthusian stagnation. Further, and in contrast to existing literature, which emphasizes the effects of changes in mortality rates, this paper focuses on the relationship between health status and the efficiency of human capital technology. Through this channel, health improvements stimulate investments in child quality in terms of both nourishing and schooling and drive the economy towards the Modern Growth regime.     

Poverty and monetary transfers in Belarus: Some options for gradual reforms

In this paper we shall be analyzing gradual poverty reducing reforms for monetary transfers in Belarus. Some evidence is offered in support of the claim that the effectiveness of the existing 'categorical' system of transfers might be improved by redirecting resources to specific groups of households. Using a decomposition of households into socio-economic groups, feasible marginal reforms are suggested, and their robustness is checked by both experimenting with different poverty lines and introducing a simplified form of labour supply responsiveness. Based on these findings, a microsimulation of a hypothetical transfer change among different groups of households is run. According to this microsimulation, all aggregate poverty indicators could be reduced.     

Model averaging in risk management with an application to futures markets

This paper considers the problem of model uncertainty in the case of multi-asset volatility models and discusses the use of model averaging techniques as a way of dealing with the risk of inadvertently using false models in portfolio management. Evaluation of volatility models is then considered and a simple Value-at-Risk (VaR) diagnostic test is proposed for individual as well as ‘average’ models. The asymptotic as well as the exact finite-sample distribution of the test statistic, dealing with the possibility of parameter uncertainty, are established. The model averaging idea and the VaR diagnostic tests are illustrated by an application to portfolios of daily returns on six currencies, four equity indices, four ten year government bonds and four commodities over the period 1991–2007. The empirical evidence supports the use of ‘thick’ model averaging strategies over single models or Bayesian type model averaging procedures.     

Designing foresight studies for Nanoscience and Nanotechnology (NST) future developments

Nanoscience and Nanotechnology (NST) is widely considered as one of the most promising areas of scientific and technological development for future decades. As a consequence, almost every country in the world has chosen to invest significantly in this area. This choice, however, is only a first step in the investment decision process, given that almost any scientific discipline can be taken at the scale of a nanometre. In this paper, it is argued that foresight studies to decide where to invest in the nanotechnology area should be designed in a different way from what is normally done. Nanotechnology, in fact, has specific characteristics that should be taken into account when evaluating its expected impacts and potentialities.     

Effects of the complementarity of child nutrition and education on persistent deprivation

This letter shows how unfavourable nutritional status may affect the evolution of income independently from its impact on life spans. Multiple steady states might emerge when it is assumed that nutrition is a component of human capital.     

Building a Sustainable Bank: The Case of GTBank of Nigeria

GTBank of Nigeria has, in just 20 years, developed into one of the most profitable and sustainable financial institutions in Africa. The case identifies the choices that helped the bank emerge successful from several shocks to the Nigerian financial sector and has implications for other financial institutions trying to balance sustainability and profitability. On the basis of eight years of research on the bank, we illustrate six factors that have characterized its success: (1) effective leadership, (2) a focus on people rather than strategy, (3) adopting a simple and focused strategy, (4) a culture of sustainable banking, (5) confronting effectively the external environment, and (6) exploitation of technology to accelerate the business. GTBank’s story raises questions about what makes a company sustainable and analyzes the decisions that executives need to make, often in challenging external circumstances, in order to preserve the long‐term sustainability of an organization. © 2014 Wiley Periodicals, Inc.     

A multiple linear regression model for imprecise information

In standard regression analysis the relationship between the (response) variable and a set of (explanatory) variables is investigated. In the classical framework the response is affected by probabilistic uncertainty (randomness) and, thus, treated as a random variable. However, the data can also be subjected to other kinds of uncertainty such as imprecision. A possible way to manage all of these uncertainties is represented by the concept of fuzzy random variable (FRV). The most common class of FRVs is the LR family (LR FRV), which allows us to express every FRV in terms of three random variables, namely, the center, the left spread and the right spread. In this work, limiting our attention to the LR FRV class, we consider the linear regression problem in the presence of one or more imprecise random elements. The procedure for estimating the model parameters and the determination coefficient are discussed and the hypothesis testing problem is addressed following a bootstrap approach. Furthermore, in order to illustrate how the proposed model works in practice, the results of a real-life example are given together with a comparison with those obtained by applying classical regression analysis.     

Relative Price Changes and Households' Welfare in Italy

The entrance of Italy in the Euro area in 2001 has given rise to a wide debate about the perception of inflation on households' well‐being. However, most of the debate has involved the measurement of the “correct” consumer price index at the national level. Much less analysis has been carried out on the distributional consequences of inflation on every household. The paper addresses this issue by performing a microsimulation analysis of the impact of inflation on Italian households in the period 1997–2007. It is shown that the impact of inflation has an ambiguous path over the period, with a large concentration of welfare losses around the introduction of the Euro currency. In particular, it is found that poorer and larger households are severely hurt by inflation and that the prices of gas and gasoline are largely responsible for determining the living conditions of Italian households.